The subject matter disclosed herein relates generally to energy management, and more particularly to energy management of household consumer appliances, as well as other energy consuming devices and/or systems in a home environment.
One or more embodiments of the invention include particular application to a hot water heater. Basic hot water heaters generally include a water reservoir or tank, a heating element such as a gas burner or an electric heating element, and a thermostat that controls the heating element to maintain a set temperature of the water in the tank. In general, the temperature of the water is maintained at a relatively constant level, corresponding to a set-point of the thermostat, until hot water is needed. As hot water is dispensed from the tank, cold water is admitted, thereby lowering the temperature of the water. When the temperature drops below the set-point of the thermostat, the heating element is activated to raise the temperature of the water.
Commonly, a water heater is used only relatively infrequently. For example, hot water demand in a residential installation may be greatest in the morning and virtually non-existent during the day. Demand may then increase again in the evening. Conventional water heaters, however, work to maintain the set point temperature regardless of hot water demand. This results in wasted energy and increased costs for consumers.